Vectorization: VectorizedOrcRecordReader does not reset VectorizedRowBatch after processing

There seems to be a memory leak in VectorizedOrcRecordReader. When 
MapColumnVector or ListColumnVector is used and the VectorizedRowBatch is not reset after every read, the vector keeps growing and spending a lot of time assigning memory. 
The reset happens in VectorizedParquetRecordReader -

https://github.com/apache/hive/blob/f78ca5df80c0bcb566f0915cda65112268df492c/ql/src/java/org/apache/hadoop/hive/ql/io/parquet/vector/VectorizedParquetRecordReader.java#L400